I have both versions of the 50-200 (ED and ED/SWD). And I have both an E-M5 and E-M1.

Both versions of the 50-200 work very well with the E-M1, although I think the SWD version is a bit quicker to focus, and a bit quieter. Nominal focus changes are very quick, comparable to m43 lenses. You just need to be aware of the E-M1 preference for vertical lines to focus.

The ED version is slow on the E-M5, nominal focus changes take as long as 2 seconds.

The SWD version is useless on the E-M5. When it's not slow, it loses focus and hunts forever. I would not recommend using this on the E-M5 for concern about burning out the focus motor.